Causality -- Consistency -- Complexity
par
Stefan Wolf
Università della Svizzera italiana, Lugano, Suisse
Jeudi 5 avril 2018, 15:30-16:30, Salle 3195, Pavillon André-Aisenstadt
Université de Montréal, 2920 Chemin de la Tour
Café avant 15:00-15:30
La conférence sera présentée en anglais
Résumé:
Quantum theory predicts correlations that question fundamental causality. Dropping the latter, while still maintaining logical consistency, has dramatic consequences for the power of communication and computation. Such reasoning is in the spirit of Landauer's famous slogan "Information is Physical". A variant of its paradigmatic rival, Wheeler's "It from Bit", is the Church-Turing hypothesis: All physical processes can be simulated on a universal Turing machine. We use the tension between the two viewpoints to look for a purely intrinsic randomness notion and find one around the second law of thermodynamics. Quantum correlations, combined with Kolmogorov complexity as randomness, may reveal an all-or-nothing nature of the Church-Turing hypothesis: Either non-Turing computations are physically impossible, or they can be carried out by "devices" as simple as individual photons.